438 CANNON: GERMINATION OF PHORADENDRON 
to the seedling in permitting it to press the tip of the radicle firmly 
against the host. 
After attachment is secured, the radicle is sent out ; it turns in 
most cases directly toward the host and comes into contact with 
FicureE I. Seeds of P. vil/osum, showing manner of attachment to the cottonwood 
branch. The shaded area represents the viscid substance which glues the seeds to the 
host. 
it, and not until then forms the expanded tip whose distal epithe- 
lium@functions as the secreting organ. The color, form and size 
of the hypocotyl in the two species of mistletoe are unlike. The 
hypocotyl of P. californicum is slender, reddish in color and may 
FicureE 2. Seedling of P. vi/lvsum on cottonwood. This seedling penetrated last 
season ; the tip of the haustorium is being transformed into a sinker for the absorption 
of water 
attain a length of .7 cm. although it is usually shorter. The hypo- 
cotyl of the other form is short, rarely much exceeding the seed- 
coat, stout and greenish in color. The structure of the hypocotyl 
in both is clearly like that of the mature plants, 7. ¢., the outer epi- 
